Toothbrush

ABSTRACT

An oral hygiene implement, typically a toothbrush, having an oral hygiene element made of a thermoplastic elastomer material having a hardness in the range ShoreA 20-50 and a composition comprising 100-200 parts of a thermoplastic elastomer base material and 10-100 parts of a plasticiser comprising a mixture of a plasticising oil and a lipophilic flavouring substance which comprises menthol and/or derivatives thereof, the lipophilic flavouring substance being 5-15 wt % of the mixture.

This invention relates to oral hygiene devices.

In particular the invention relates to toothbrushes of the type whichincorporate elastomeric lamellae on the surface of their head oppositeto the surface from which bristles project. Such lamellae are providedprimarily for the purposes of tongue cleaning, i.e. for gently removingdeposits which might cause bad breath from the tongue.

Toothbrushes of this type are known, see for example GB-A-2 391 462which discloses a toothbrush having a head with bristles extending fromone surface of its head, and thermoplastic elastomeric lamellaeextending from the opposite surface, and these elastomeric lamellae mayincorporate a flavour. Such a toothbrush, though not incorporating aflavour into its elastomeric lamellae, is sold by the present applicantfor example under the trade mark Dr.BEST™ Duo Protekt.

There remains an ongoing need to provide improved forms of suchtoothbrushes, and it is an objective of this invention to provide suchan improvement.

According to this invention an oral hygiene implement is provided,having at least one elastomeric oral hygiene element made of athermoplastic elastomer material having a hardness in the range ShoreA20-50 and a composition comprising 100-200 parts of a thermoplasticelastomer base material and 10-100 parts of a plasticiser comprising amixture of a plasticising oil and a lipophilic flavouring substancewhich comprises menthol and/or derivatives thereof, the lipophilicflavouring substance being 5-15 wt % of the mixture.

An improvement provided by the invention is the enhanced oral experienceprovided by the pleasant flavour resulting from the presence of thelipophilic flavouring substance.

The oral hygiene implement preferably comprises a plastics materialhandle part upon which the one or more oral hygiene element is mounted.Suitable plastics materials include the plastics materials from whichtoothbrushes are made, typically polypropylene.

The oral hygiene implement is preferably a toothbrush comprising a griphandle and an integral or replaceable head with bristles extending fromone surface of its head. Preferably the at least one elastomeric oralhygiene element comprises thermoplastic elastomeric lamellae extendingfrom the opposite surface of the head. Such lamellae may be of a knownshape. For example such lamellae may be in the form of strips having alength direction perpendicular to the head-handle length direction ofthe toothbrush, a width direction perpendicular to the said oppositesurface, and a thickness direction parallel to said head-handledirection. A typical form of such lamellae is those of the knownDr.BEST™ Duo Protekt toothbrush.

Alternatively the oral hygiene implement may be a tongue cleaning deviceother than a toothbrush. An example of such a device is for exampledisclosed in PCT/EP06/000181 and DE-G-202 005 004291.9, relating to the“Zungen Reiniger” tongue cleaning device sold under the “DrBEST™” trademark.

Thermoplastic elastomer materials are well known materials which combinethe characteristics of both thermoplastics on the one hand andelastomers on the other. Numerous types of thermoplastic elastomer basematerial are known for use in the oral hygiene implement of thisinvention, for example styrene block copolymers. A suitable basematerial is that which is used as the base thermoplastic elastomermaterial used for the tongue-cleaning lamellae of the AQUAFRESH DUOCLEAN™ toothbrush marketed by the present applicant. Examples of suchmaterials are he Thermolast K™ family of thermoplastic elastomermaterials available from the supplier Gummiwerk Kraiburg GmbH & Co. KG,Germany, for example the material TF 3 AAH. These are based onhydrogenated styrene block copolymers.

The thermoplastic elastomer material preferably has a hardness in therange ShoreA 30+/−3.

Preferably the thermoplastic elastomer material contains 20-80 parts ofthe plasticiser. The composition range of the plasticiser, i.e. 5-15 wt% of the lipophilic flavouring substance in the plasticiser mixtureappears to be important in optimising the taste perceived by the user ofthe oral hygiene implement of this invention. A preferred proportion is10+/−2%. For example it is typically found that if less than 5% is usedlittle benefit in taste may be experienced, and if more than 15% is usedthe taste may be undesirable.

The term “plasticising oil” used herein is intended to encompass alloils which are capable of plasticising the thermoplastic elastomermaterial. The term “oil” as used herein is intended to encompass allorganic liquids having a plasticising function, including paraffinic,hydrocarbon and ester-based oils. The viscosity of such oils may varybetween a mobile liquid and a wax. For use in the head of a toothbrushthe oil must be of a non-toxic orally acceptable type, and a suitableplasticising oil is so called medical white oil. Medical white oil is aknown plasticising oil for thermoplastic elastomer materials and ispreferred. Typically a medical white oil comprises a highly refinedmineral oil conforming to the quality requirements of the British and USPharmacopoeias. Typically such oils comply with the quality requirementsof “Mineral Hydrocarbons in Food Regulations” 1996; (S.I.No. 1073), andUnited States F & D. A Regulations No. 178.3620(a) and 172.878.Typically such oils have the following properties:

ISO 15 ISO 68 Relative Density @ 60° F. 0.850 0.880 Viscosity @ 20° C.(cS) 25.0 235 Viscosity @ 40° C. (cS) 15.0 69.0

Suitably the lipophilic flavouring substance comprises 70 weight % ormore, preferably 80 weight % or more of menthol and/or derivativesthereof. For use in the head of a toothbrush the derivative must be of anon-toxic orally acceptable type. Many such non-toxic orally acceptablecompounds derived from the menthol nucleus are known. Suitablederivatives may include esters of menthol, e.g. C₁₋₅ alkanoic acidesters, ether and ketone derivatives in which the hydroxyl group of thementhol nucleus is replaced by a carbonyl moiety or is cyclised into anether, e.g. furan, moiety. Preferably the lipophilic flavouringsubstance comprises 40-60 weight % of menthol, preferably in mixturewith 20-35 weight % of menthone, preferably in mixture with 5-8 weight %of one or more menthyl ester, particularly menthyl acetate, preferablyin mixture with 1-5 weight & of menthofuran. An example of such asubstance is Peppermint Oil. Peppermint oil generally comprises thecomposition:

Minimum Maximum Total menthol  52 wt. %  56 wt. % Menthone  22 wt. %  30wt. % Menthyl esters 5.8 wt. % 7.8 wt. % Menthofuran 1.7 wt. % 3.7 wt. %

Typically in peppermint oil the menthofuran is the (R)-(+)-isomer. Afurther constituent of peppermint oil is the menthol derivative(R)-(+)-pulegone.

In addition to being pleasant, the flavour of menthol and mentholderivatives also conveys a feeling of oral freshness, and can assist inovercoming any problem of bad breath.

The lipophilic flavouring substance may be admixed with the plasticisingoil to form the plasticiser, and the mixture then blended with thethermoplastic elastomer. Alternatively the lipophilic flavouringsubstance and the plasticising oil may be blended separately with thethermoplastic elastomer.

The oral hygiene implement with its oral hygiene element may be madeaccording to any of the known processes for making such an implement. Atypical manufacturing process comprises co-moulding of the implementfrom a plastics material and the thermoplastic elastomer material. Insuch a process the thermoplastic elastomer material defined above foruse in the invention may be co-moulded by a moulding process analogousto that used for conventional materials. An example of such aco-moulding process is disclosed in WO-A-2005/084487.

In a further aspect the present invention therefore provides a processfor making an oral hygiene implement comprising a plastics materialhandle part and an oral hygiene element, comprising co-moulding theplastics material handle part and an oral hygiene element made of athermoplastic elastomer material having a hardness in the range ShoreA20-50 and a composition comprising 100-200 parts of the thermoplasticelastomer base material and 10-100 parts of a plasticiser comprising amixture of a plasticising oil and a lipophilic flavouring substancewhich comprises menthol and/or derivatives thereof, the lipophilicflavouring substance being 5-15 wt % of the mixture.

The process may be otherwise generally conventional. Typically such aprocess comprises firstly making a plastics material part of thetoothbrush in a first injection mould, then enclosing the so-madeplastics material part in a second injection mould having a mould cavitywhich defines the shape of the elastomeric oral hygiene element, theninjecting the thermoplastic elastomer material into the second mouldunder conditions which achieve a bond between the plastics material andthe thermoplastic elastomer. Typical plastics materials are known in theart of toothbrush manufacture, e.g. the plastics materials from whichthe plastics material parts of the Dr.BEST™ Duo Protekt toothbrush ismade and include polypropylene.

The oral hygiene implement of this invention is preferably provided forsale in some suitable packaging, e.g. blister packaging. It has beenfound that some lipophilic flavouring substances, particularly thoseincluding menthol, can adversely affect pigments used on packaging,especially blue pigments, and the invention further addresses thisproblem.

This problem is addressed by a package comprising a packaging layerhaving a surface on which is printed matter incorporating a pigment, andthis printed matter is covered by a barrier layer comprising at leastone layer each of polyvinyl alcohol and polyethylene, the barrier layerbeing situated between the printed matter and the oral hygieneimplement.

Further there is provided a product comprising an oral hygiene implementas defined above, enclosed within a package comprising a packaging layerhaving a surface on which is printed matter incorporating a pigment,this printed matter is covered by a barrier layer comprising at leastone layer each of polyvinyl alcohol and polyethylene, and this barrierlayer is situated between the printed material and the oral hygieneelement.

It is found that the interposition of such a barrier layer between theoral hygiene element and the printed matter helps to prevent adverseeffects of the flavouring on typical pigments used in printed matter onpackaging.

Suitably the packaging layer may comprise a cardboard-aluminium foillaminate, with the printed matter printed on the surface of thealuminium foil layer. Preferably the barrier layer comprises two layersof polyethylene sandwiching a layer of polyvinyl alcohol intermediatebetween these two layers.

The present invention will now be illustrated by way of example onlywith reference to the accompanying drawings.

FIG. 1 shows an overall side view of an oral hygiene device of thisinvention, being a toothbrush.

FIG. 2 shows an overall side view of a package for the oral hygienedevice of FIG. 1.

FIG. 3 shows an enlarged cross section of the construction of part ofthe package of FIG. 2

Referring to FIG. 1 an oral hygiene implement 1 overall is shown, beinga toothbrush, comprising a grip handle 2 and an integral head 3 withbristles 4 extending from one surface 5 of its head 3. The handle 2 andhead 3 are made of a known polypropylene material, e.g. Moplen EP 548 T™used in toothbrush manufacture.

Elastomeric oral hygiene elements 6 are provided on head 3, beingthermoplastic elastomeric lamellae extending from the opposite surface 7of the head 3 from which the bristles 4 extend. The lamellae 6 areidentical in construction to those of the known Dr.BEST™ Duo Protekttoothbrush, i.e. extending ca. 2 mm from the surface 7, and about 1 mmwide at their base where they meet the surface 7. The lamellae 6 areformed integrally in one piece with a covering 8 of elastomer over thehead 3.

The lamellae 6 and covering 8 are made of a thermoplastic elastomermaterial having a hardness of ShoreA 30 comprising 100-200 parts of athermoplastic elastomer base material, for example Thermolast K™ TF3AAH, and 10-100 parts of plasticiser. Specifically thermoplasticelastomer materials comprising respectively 120 parts of thethermoplastic elastomer base material and 20 parts of the plasticiser;and 200 parts of the thermoplastic elastomer base material and 100 partsof the plasticiser were used.

In each of these compositions of the thermoplastic elastomer materialthe plasticiser comprises a mixture of Medical white oil complying withthe quality requirements of “Mineral Hydrocarbons in Food Regulations”1996; (S.I.No. 1073), and United States F & D. A Regulations No.178.3620(a) and 172.878, with the following properties:

ISO 15 ISO 68 Relative Density @ 60° F. 0.850 0.880 Viscosity @ 20° C.(cS) 25.0 235 Viscosity @ 40° C. (cS) 15.0 69.0This oil is mixed with peppermint oil of a composition:

Minimum Maximum Total menthol  52 wt. %  56 wt. % Menthone  22 wt. %  30wt. % Menthyl esters 5.8 wt. % 7.8 wt. % Menthofuran 1.7 wt. % 3.7 wt. %

In the mixture the peppermint oil amounts to 10 weight % of the whitemedical oil-peppermint oil mixture.

The plastics material part of the toothbrush, i.e. the handle 2 and head3 were made by a conventional injection moulding process. This plasticsmaterial part was then enclosed in an injection mould (not shown) havinga mould cavity (not shown) defining the shape of the lamellae 6, andthermoplastic elastomer material of this composition was injectionmoulded to form the lamellae 6. The procedure was exactly the same wayas the known elastomer material compositions which use the same whitemedical oil without the peppermint oil as plasticiser, i.e. in the sameway as the lamellae of the known Dr.BEST™ Duo Protekt toothbrush. Thisis advantageous in enabling a 1:1 replacement of the known thermoplasticelastomer material of the Dr.BEST™ Duo Protekt toothbrush with thepeppermint oil containing material described above. The proportion of 10weight % peppermint oil in the plasticiser is found to be optimal inachieving a taste that is satisfactory to consumers.

Referring to FIGS. 2 and 3 a package 10 overall suitable for atoothbrush 1 above is shown. This package comprises a polyethyleneterephthalate blister 11 being 250 microns thick defining a typicalblister cavity 12 suitable to enclose the toothbrush 1. The blistercavity 12 is closed by a packaging layer 13, which comprises a cardboard13A-aluminium foil 13B laminate, with the printed matter 14 printed onthe surface of the aluminium foil layer 13B. This packaging layer 13 istypically 300-400 microns thick, for example ca. 350 microns thick. Thisprinted matter 14 is covered by a barrier layer 15 comprising two layers15A, 15B of polyethylene sandwiching a layer of polyvinyl alcohol 15Cintermediate between these two layers 15A, 15B. The barrier layer 15 istypically 40-60 microns thick, typically ca. 50 microns thick.

1. An oral hygiene implement, having at least one elastomeric oralhygiene element made of a thermoplastic elastomer material having ahardness in the range ShoreA 20-50 and a composition comprising 100-200parts of a thermoplastic elastomer base material and 10-100 parts of aplasticiser comprising a mixture of a plasticising oil and a lipophilicflavouring substance which comprises menthol and/or derivatives thereof,the lipophilic flavouring substance being 5-15 wt % of the mixture. 2.An oral hygiene implement according to claim 1 being a toothbrushcomprising a grip handle and an integral or replaceable head withbristles extending from one surface of its head, and the at least oneelastomeric oral hygiene element comprises thermoplastic elastomericlamellae extending from the opposite surface of the head.
 3. An oralhygiene implement according to claim 1 wherein the plasticizing oilcomprises medical white oil.
 4. An oral hygiene implement according toclaim 1 wherein the lipophilic flavouring substance comprises 10+/−2% ofthe plasticiser.
 5. An oral hygiene implement according to claim 1wherein the lipophilic flavouring substance comprises 70 weight % ormore of menthol and/or one or more derivative thereof.
 6. An oralhygiene implement according to claim 5 wherein the lipophilic flavouringsubstance comprises 40-60 weight % of menthol, in mixture with 20-35weight % of menthone, 5-8 weight % of one or more menthyl esterparticularly menthyl acetate, and 1-5 weight of menthofuran.
 7. An oralhygiene implement according to claim 6 wherein the lipophilic flavouringsubstance comprises the composition: Minimum Maximum Total menthol  52wt. %  56 wt. % Menthone  22 wt. %  30 wt. % Menthyl esters 5.8 wt. %7.8 wt. % Menthofuran 1.7 wt. % 3.7 wt. %


8. An oral hygiene implement according to claim 1 wherein the lipophilicflavouring substance comprises peppermint oil.
 9. A process for makingan oral hygiene implement comprising a plastics material handle part andan oral hygiene element, comprising co-moulding the plastics materialhandle part and an oral hygiene element made of a thermoplasticelastomer material having a hardness in the range ShoreA 20-50 and acomposition comprising; 100-200 parts of a thermoplastic elastomer basematerial and 10-100 parts of a plasticiser comprising a mixture of aplasticising oil and a lipophilic flavouring substance which comprisesmenthol and/or derivatives thereof, the lipophilic flavouring substancebeing 5-15 wt % of the mixture.
 10. An article comprising an oralhygiene implement according to claim 1 provided in packaging comprisinga packaging layer having a surface on which is printed matterincorporating a pigment, and this printed matter is covered by a barrierlayer comprising at least one layer each of polyvinyl alcohol andpolyethylene, the barrier layer being situated between the printedmatter and the oral hygiene implement.
 11. An article according to claim10 wherein the barrier layer comprises two layers of polyethylenesandwiching a layer of polyvinyl alcohol intermediate between these twolayers of polyethylene.
 12. An article according to claim 10 wherein thebarrier layer has a thickness 40-60 microns.